﻿#region License
// Copyright (c) 2007 James Newton-King
//
// Permission is hereby granted, free of charge, to any person
// obtaining a copy of this software and associated documentation
// files (the "Software"), to deal in the Software without
// restriction, including without limitation the rights to use,
// copy, modify, merge, publish, distribute, sublicense, and/or sell
// copies of the Software, and to permit persons to whom the
// Software is furnished to do so, subject to the following
// conditions:
//
// The above copyright notice and this permission notice shall be
// included in all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
// EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
// OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
// NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
// HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
// WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
// FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
// OTHER DEALINGS IN THE SOFTWARE.
#endregion

#if !PocketPC && !SILVERLIGHT
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Reflection;
using Lib.JSON.Utilities;
using System.Globalization;

namespace Lib.JSON.Serialization
{
  /// <summary>
  /// Get and set values for a <see cref="MemberInfo"/> using dynamic methods.
  /// </summary>
  public class DynamicValueProvider : IValueProvider
  {
    private readonly MemberInfo _memberInfo;
    private Func<object, object> _getter;
    private Action<object, object> _setter;

    /// <summary>
    /// Initializes a new instance of the <see cref="DynamicValueProvider"/> class.
    /// </summary>
    /// <param name="memberInfo">The member info.</param>
    public DynamicValueProvider(MemberInfo memberInfo)
    {
      ValidationUtils.ArgumentNotNull(memberInfo, "memberInfo");
      _memberInfo = memberInfo;
    }

    /// <summary>
    /// Sets the value.
    /// </summary>
    /// <param name="target">The target to set the value on.</param>
    /// <param name="value">The value to set on the target.</param>
    public void SetValue(object target, object value)
    {
      try
      {
        if (_setter == null)
          _setter = DynamicReflectionDelegateFactory.Instance.CreateSet<object>(_memberInfo);

#if DEBUG
        // dynamic method doesn't check whether the type is 'legal' to set
        // add this check for unit tests
        if (value == null)
        {
          if (!ReflectionUtils.IsNullable(ReflectionUtils.GetMemberUnderlyingType(_memberInfo)))
            throw new Exception("Incompatible value. Cannot set {0} to null.".FormatWith(CultureInfo.InvariantCulture, _memberInfo));
        }
        else if (!ReflectionUtils.GetMemberUnderlyingType(_memberInfo).IsAssignableFrom(value.GetType()))
        {
            throw new Exception("Incompatible value. Cannot set {0} to type {1}.".FormatWith(CultureInfo.InvariantCulture, _memberInfo, value.GetType()));
        }
#endif

        _setter(target, value);
      }
      catch (Exception ex)
      {
        throw new JsonSerializationException("Error setting value to '{0}' on '{1}'.".FormatWith(CultureInfo.InvariantCulture, _memberInfo.Name, target.GetType()), ex);
      }
    }

    /// <summary>
    /// Gets the value.
    /// </summary>
    /// <param name="target">The target to get the value from.</param>
    /// <returns>The value.</returns>
    public object GetValue(object target)
    {
      try
      {
        if (_getter == null)
          _getter = DynamicReflectionDelegateFactory.Instance.CreateGet<object>(_memberInfo);

        return _getter(target);
      }
      catch (Exception ex)
      {
        throw new JsonSerializationException("Error getting value from '{0}' on '{1}'.".FormatWith(CultureInfo.InvariantCulture, _memberInfo.Name, target.GetType()), ex);
      }
    }
  }
}
#endif